Prognostic importance of coronary anatomy and left ventricular ejection fraction despite optimal therapy: Assessment of residual risk in the Clinical Outcomes Utilizing Revascularization and Aggressive DruG Evaluation Trial

Background It is unknown if baseline angiographic findings can be used to estimate residual risk of patients with chronic stable angina treated with both optimal medical therapy (OMT) and protocol-assigned or symptom-driven percutaneous coronary intervention (PCI). Methods Death, myocardial infarction (MI), and hospitalization for non-ST-segment elevation acute coronary syndrome were adjudicated in 2,275 COURAGE patients. The number of vessels diseased (VD) was defined as the number of major coronary arteries with ≥50% diameter stenosis. Proximal left anterior descending, either isolated or in combination with other disease, was also evaluated. Depressed left ventricular ejection fraction (LVEF) was defined as ≤50%. Cox regression analyses included these anatomical factors as well as interaction terms for initial treatment assignment (OMT or OMT + PCI). Results Percutaneous coronary intervention and proximal left anterior descending did not influence any outcome. Death was predicted by low LVEF (hazard ratio [HR] 1.86, CI 1.34-2.59, P <.001) and VD (HR 1.45, CI 1.20-1.75, P <.001). Myocardial infarction and non-ST-segment elevation acute coronary syndrome were predicted only by VD (HR 1.53, CI 1.30-1.81 and HR 1.24, CI 1.06-1.44, P =.007, respectively). Conclusions In spite of OMT and irrespective of protocol-assigned or clinically driven PCI, LVEF and angiographic burden of disease at baseline retain prognostic power and reflect residual risk for secondary ischemic events.